The present invention relates to highly effective liquid, concentrated, homogeneous, builder-free heavy-duty detergent compositions. These compositions comprise an anionic synthetic surfactant, an ethoxylated nonionic surfactant, a cationic surfactant and a liquid carrier. The majority of the ternary active mixture is comprised of the anionic synthetic surfactant. In the description of the invention, the terms "ternary active system" and "ternary active mixture" are used interchangeably. An effective suds regulant system suitable for effective suds control under laundry conditions favorable to suds-formation, for example in automatic washing machine laundering at temperatures in the range from 60.degree. C.-90.degree. C., is also described. This suds regulant system unexpectedly provides "prolonged" suds-regulation as for example can be needed to avoid rinsing suds-problems due to surfactant carry over. The suds regulant is comprised of a silicone suds suppressant and a saturated fatty acid.
The effectiveness of liquid detergent compositions depends upon a large series of factors such as the intended usage conditions inclusive of concentration, type of laundering operations, surfactant concentration, type of machine or topical application. In addition, it is required that these compositions remain stable and homogeneous under a broad range of storage conditions and during manipulation in the distribution system.
Liquid, heavy-duty detergent compositions containing a synthetic organic detergent compound, which is generally anionic, nonionic or mixed anionic-nonionic in nature; an inorganic builder salt; and a solvent, are disclosed, for example, in U.S. Pat. Nos. 2,551,634; 2,908,651; 2,920,045; 2,947,702; 3,239,468; 3,272,753; 3,393,154; 3,554,916; 3,697,451; 3,709,838; Belgian Pat. Nos. 613,165, 665,532; 794,713 and 817,267; British Pat. Nos. 759,877; 842,813; and German Application Nos. 16 17 119; 19 37 682; 23 27 861; 23 30 840; 23 61 448; and 23 62 114. These compositions frequently contain a hydrotrope or solubilizing agent to permit the addition of sufficient quantities of surfactants and usual builder salts to provide a reasonable volume usage/performance ratio. Substantially anhydrous liquid compositions containing an alkanolamine component are known from U.S. Pat. No. 3,528,925. Soap containing liquid compositions are disclosed in U.S. Pat. No. 2,875,153 and 2,543,744. It has also been suggested (French Pat. Nos. 2,343,804 and 2,343,805) that effective concentrated liquid detergent compositions can be prepared containing high levels of nonionic ethoxylated surfactants.
Notwithstanding the investment of substantial research efforts aimed at developing built and builder-free liquid detergent compositions, there are several problems associated with the art-disclosed compositions which render them less optimal for wide scale use, undesirable from an ecological standpoint in improperly treated sewage, objectionable from a performance point of view in cleaning both natural and synthetic fibers and subject to instability under sever storage conditions. Consequently, there is a standing desire to generally improve these liquid detergents especially builder-free concentrated liquid detergents with a view to adapt them, as per se substitutes for granular detergents, for wide-scale use over a broad range of laundering conditions.
While known highly concentrated liquid detergent compositions require the utilization of high levels of nonionic surfactants, especially nonionic ethoxylates, with a view to achieve consumer acceptable performance particularly greasy and oily stain removal, such formulae could deserve improvement with respect to other important performance and utilization factors inclusive of bleach-sensitive and proteinaceous stain removal. It is also known that high levels of nonionic ethoxylates can give rise to processing difficulties, especially relative to the avoidance of phase separation, high chill points and the homogeneous incorporation of minor ingredients. Well-known usage difficulties inherent to high levels of nonionics relate to effective suds-control and rinsing in any washing step. In fact, the difficulties inherent to commercially viable concentrated builder-free liquid detergents require a balancing of a series of factors inclusive of: ease-of-processing, suds levels adapted to washing machines, superior performance for a broad range of stains under varying usage conditions, and stability over prolonged periods of storage.
It has been found that superior detergency, in particular with respect to greasy-oily stains, suds-control, ease-of-processing and storage stability is obtained from concentrated heavy-duty liquid detergent compositions containing a ternary anionic/nonionic/cationic surfactant system the majority of which is represented by the anionic detergent, and a liquid carrier.
It has also been found that a specific suds regulant system containing a silicone suds suppressant, and a saturated fatty acid are especially effective for suds control under severe conditions inclusive of the avoidance of suds problems in the rinse as a result of surfactant carry over.
It is a main object of the invention to provide liquid concentrated builder-free heavy-duty detergent compositions which can be used in lieu of granular built detergent compositions over a wide range of laundering conditions.
It is another object of this invention to formulate highly effective concentrated builder-free liquid detergent compositions which can easily be made and, remain homogeneous and, in general do not loose their effectiveness over prolonged periods of storage.
These objects have now been resolved as can be seen from the following description of the invention.